ABB Relion 670 series - Directional Phase Overcurrent Protection, Four Steps OC4 PTOC(51_67)

The protection function can be used for the specific application only if this setting value
is equal or less than the maximum phase fault current that the IED has to clear.
The IED setting value Pickup is given in percentage of the primary base current value,
IBase. The value for Pickup is given from this formula:
100
Is
Pickup
IBase
= ×
ANSIEQUATION1147 V1 EN (Equation 448)
9.2 Directional phase overcurrent protection, four steps
OC4PTOC(51_67)
9.2.1 Identification
Function description IEC 61850
identification
IEC 60617
identification
ANSI/IEEE C37.2
device number
Directional phase overcurrent
protection, four steps
OC4PTOC
TOC-REVA V2 EN
51_67
9.2.2 Application
Directional phase overcurrent protection, four steps OC4PTOC (51_67) is used in several
applications in the power system. Some applications are:
• Short circuit protection of feeders in distribution and subtransmission systems.
Normally these feeders have a radial structure.
• Back-up short circuit protection of transmission lines.
• Back-up short circuit protection of power transformers.
• Short circuit protection of different kinds of equipment connected to the power
system such as; shunt capacitor banks, shunt reactors, motors and others.
• Back-up short circuit protection of power generators.
In many applications several steps with different current pickup levels and time delays are
needed. OC4PTOC (51_67) can have up to four different, individually settable steps. The
following options are possible:
Section 9 1MRK 506 369-UUS -
Current protection
492 Line distance protection REL670 2.2 ANSI
Application manual